However this page should be named the "Queen" part violates T:HONOUR, so it can't use that one.
Talk about it here.
A Zygon was part of the group stuck on Earth. Their ship landed in 1562, and one of the group disguised as a horse which was ridden by Queen Elizabeth I and the Tenth Doctor. It attacked Elizabeth and took her form but was later killed by her. (TV: The Day of the Doctor)